The present invention relates to electronic devices suitable for being used as, for example, devices which are removably provided with respect to a main unit in order to perform arbitrary functions, and to units using the same. More particularly, the present invention relates to an electronic device which has an equivalent shape to a memory card or a similar semiconductor memory and which is connected to a connecting section of a main unit in order to perform arbitrary functions, and to a unit using the same.
An electronic device is available which, for example, has an equivalent shape to a memory card which is removably provided with respect to a main unit or to a similar semiconductor memory. The electronic device is connected to a memory connecting section of the main unit in order to perform arbitrary functions. Specifically, such an electronic device adds on a connecting function for a computer network or a function of communicating with an external unit. In this way, the electronic device easily enhances the operation and application of the main unit.
Concerning such an electronic device, current consumption in executing a function greatly varies according to the type of function provided in the electronic device. Specifically, for example, when executing the above-described connecting function for a computer network or the function of communicating with an external unit, it requires a several-fold increase of current consumption compared with that required in executing a conventional memory function. When the electronic device which requires such a high current consumption is inserted into a main unit which is dedicated for electronic devices having the conventional memory function, an internal battery may be exhausted due to the excessive flow of current, or the function cannot be performed due to a decrease in the supply voltage. In the worst case, the main unit may be damaged.
In order to prevent these problems, the shape of the connecting section between the electronic device and the main unit is made different from that in which the electronic device is dedicated for the memory function. In this way, an electronic device having a different current consumption is not inserted into the main unit. However, such measures require a difficult process of reshaping the connecting section. When an electronic device having yet a larger current consumption is manufactured in the future, it will be necessary to again make the form of the connecting section different. In short, these measures do not lead to a fundamental solution.
The problems with the conventional electronic device and the main unit include the exhaustion of an internal battery in a short period of time due to the excessive flow of current when an electronic device having a different current consumption is inserted into the main unit and is used. A function may be disabled due to a reduction in the supply voltage, and, in the worst case, the main unit may be damaged. These problems cannot be solved by simply reshaping the connecting section in accordance with current consumption.